NEC

About: NEC is a company organization based out in Tokyo, Japan. It is known for research contribution in the topics: Signal & Layer (electronics). The organization has 33269 authors who have published 57670 publications receiving 835952 citations. The organization is also known as: NEC Corporation & NEC Electronics Corporation.

Method for manufacturing bump leaded film carrier type semiconductor device

Abstract: An insulating film has conductive layers on a first surface and conductive protrusions on a second surface. The conductive layers are connected to the conductive protrusions via through holes provided in the insulating film. A semiconductor chip having pads is adhered by an adhesive layer to the insulating film. Then, the conductive layers are locally pressured, so that the conductive layers are electrically connected to respective ones of the pads.

Electronic ticket issuing system and electronic ticket issuing method

Abstract: An electronic ticket issuing system and an electronic ticket issuing method for simplifying authentication procedures by the use of biological information such as a fingerprint and voiceprint First, a ticket buyer sends a request for ticket purchase to a ticket issuing center using his/her mobile terminal The ticket issuing center transmits a request for issue of an electronic certificate to request an authentication department to issue an electronic certificate The authentication department creates an electronic certificate to which the biological information about the ticket buyer is added The ticket issuing center transmits an electronic ticket including the electronic certificate to the mobile phone When the ticket buyer participates in an event with the electronic ticket, the ticket buyer transmits the electronic ticket with the biological information to an authentication terminal In addition, the ticket buyer inputs his/her biological information at the moment into the authentication terminal Subsequently, the authentication terminal compares the two pieces of biological information for authentication Since the electronic ticket includes the biological information, the authentication terminal can perform high-security authentication without exchanging the biological information with the authentication department via a network

Improved power performance for a recessed-gate AlGaN-GaN heterojunction FET with a field-modulating plate

Abstract: A recessed-gate AlGaN-GaN field-modulating plate (FP) field-effect transistor (FET) was successfully fabricated on an SiC substrate. By employing a recessed-gate structure on an FP FET, the transconductance was increased from 150 to 270 mS/mm, leading to an improvement in gain characteristics, and current collapse was minimized. At 2 GHz, a 48-mm-wide recessed FP FET exhibited a record output power of 230 W (4.8 W/mm) with 67% power-added efficiency and 9.5-dB linear gain with a drain bias of 53 V.

Piezoelectric diaphragm and piezoelectric speaker

Abstract: Disclosed is a piezoelectric diaphragm with a transparent piezoelectric member and a transparent electrode. Also disclosed is a portable electronic device that has a display means to display an image and a piezoelectric speaker having a transparent piezoelectric member and a transparent electrode. In this portable electronic device, the piezoelectric speaker is disposed in front of the display means.

A1N Substrates with High Thermal Conductivity

Abstract: A new aluminum nitride (AIN) substrate, which has high thermal conductivity of 160 W/mK at room temperture, has been developed using the hot press sintering technique. The new AIN substrate has the following excellent characteristics. 1) The thermal conductivity is eight times as high as that of AI 2 O 3 at room temperature and is almost equal to that of 99.5 percent BeO at 150°C. 2) The thermal expansion coefficient is smaller than that of AI 2 O 3 and BeO, and is close to that of a silicon semiconductor chip. 3) The electrical properties are almost as good as those for AI 2 O 3 and BeO in the wide frequency range. 4) It not only has higher mechanical stength but also easier machinable property than AI 2 O 3 . It is characterized by its light transparency from visible light to the infrared wavelength region. It was proved that the new AIN substrate is able to be metallized with good adhesion strength by the conventional evaporating method and the conventional sputtering method. The new AIN was found to be applicable to three kinds of semiconductor devices: 1) silicon epitaxial transistor, 2) GaAIAs light emitting diode, and 3) InGaAsP laser diode. Also, another AIN substrate was developed using the normal sintering technique, which has high thermal conductivity of 140 W/mK at room temperature.